Summerville, South Carolina (CNN)Even for Donald Trump, it was a dangerous political high-wire act.

Days after a blowout victory in New Hampshire, the Republican presidential front-runner stood on the debate stage in South Carolina and accused former President George W. Bush of lying about the existence of weapons of mass destruction in Iraq. He also faulted the former president for the terrorist attacks of September 11, 2001, that brought down the World Trade Center.

"That's not keeping us safe," Trump argued.

Right away, it was clear that those charges would not sit well with many in this Southern state, home to a large population of military personnel and veterans. The audience in the Greenville auditorium booed the New York businessman, and undecided voters expressed a mixture of disbelief and disdain in the days that followed.

For any other politician, it could have been a campaign-ending moment. Instead, it underscored Trump's unique ability to make statements that would sink anyone else but still come out on top. He easily won the South Carolina primary on Saturday, beating the runner-up by about 10 points. And the former president's brother, Jeb, dropped his bid for the presidency after a disappointing showing.

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The South Carolina race demonstrates the broader debate inside a Republican party that's being rocked by Trump's rise. In interviews with nearly 30 South Carolina voters this week, everyone expressed unease about Trump's comments. Trump's supporters, or those who were leaning toward him, said the incident didn't sway their support. Undecided voters were less forgiving.

Sixty-six-year-old Trump supporter James Sheaffer defended the 43rd president as a "fine man who took care of the country" at a Trump rally in Beaufort.

But, Sheaffer added: "I just don't think we have time and room for another Bush. I think the country needs a change."

Bill Balyo, a 66-year-old Trump supporter with a home in Hilton Head Island, said Trump "went a little too far" in his comments about Bush.

After pausing to give it a little more thought, Balyo came to this conclusion: "Everything Trump says if you really analyze it has a little sense to it."

Sean Higgins, a college professor from Lexington, voted for Trump Saturday -- despite saying that he was very "bothered" by Trump's remarks about George W. Bush.

"His crassness bothers me, his vulgarity bothers me. This is going to be someone who will be our commander in chief," Higgins said. But the controversy wasn't enough to make Higgins choose a different candidate.

"When you vote for Trump, it's almost giving the middle finger to the establishment or the status quo," he said.

But Penny Merriman, a retired school board member, was struggling to decide between Marco Rubio and Trump. At a Rubio event in Summerville on Wednesday, Merriman said Trump's comments about the World Trade Center seriously hurt her opinion of the candidate.

"So far for me, that's the only mistake that Trump has made," Merriman, 63, said. "Huge."

For another undecided voter, Dana Overton, Trump's debate comments persuaded her to take Trump permanently off the list of GOP candidates she would consider supporting.

"To say that he would lie -- I don't think Bush would lie about that. It was offensive and disrespectful," Overton, 51, said at a Jeb Bush campaign event in Summerville. September 11, she added, was "so personal to all of us."

Beth Richbourg of West Columbia, who voted for Bush on Saturday, said that it wasn't just the military community that took offense.

"You don't have to be military to have an opinion on that. I thought that was very rude to come after the president on that. Very rude and very wrong," she said.

Grace and Thomas Spangler both took issue with Trump's remarks — but said at a Trump rally in Walterboro this week that they would still back the businessman.

"I think Bush did a good job. He didn't know it was actually going to happen," Thomas Spangler said about the 9/11 attacks. Still, Spangler said he appreciates Trump's willingness to "fight the GOP establishment."

Grace Spangler chimed in: "I thought (Trump's comments) were uncalled for and a low blow, but it wouldn't change my mind on who I vote for."

A show of strength

Trump's win is particularly symbolic in a state that has predicted the GOP's eventual nominee every presidential cycle except 2012, when Newt Gingrich swept the state.

All week, the Republican field of candidates have jockeyed to win over the military and veterans communities -- including Trump.

Repeating a line he has used throughout the campaign, Trump vowed to "knock the hell out of ISIS" and take care of the country's veterans. But he also doubled down on his swipes at George W. Bush from Saturday's debate.

At a CNN town hall in Columbia on Thursday, Trump stopped short of repeating the claim that George W. Bush had lied about Iraq. But Trump said he had doubts about the arguments Bush made for the war -- "Something was going on," he said cryptically -- and he again slammed the former president for making the "worst decision" to invade Iraq.

Trump had competition in the national security arena: Ted Cruz delivered a major address on defense issues aboard the USS Yorktown, promising to strengthen the country's military.

Rubio warned at campaign stops that national security was at stake in the 2016 election, and talked up his experience on the Senate Foreign Relations and Intelligence Committees.

Lindsey Graham, a retired Air Force reservist, stumped for Jeb Bush around his home state, billing the ex-governor the candidate most qualified to be a "wartime president" -- unlike Trump. At a Bush event this week, the South Carolina senator rallied the audience, asking: "How many of you believe that George W. Bush was not responsible for 9/11?"

When the crowd yelled out to express agreement, Graham warned: "Do you want to nominate someone who can't pass that test?"

Winning in Bush country

No candidate was more stung by Trump's victory than Jeb Bush.

Both Bush's brother, George W. Bush, and his mother, former first lady Barbara Bush, campaigned for him in South Carolina. The former Florida governor feistily hit back at Trump's knocks at his brother's legacy, and even appeared energized by the confrontation.

"The more outlandish things he says about my brother... knowing about 9/11 -- you can't make this stuff up," Bush said at a country club in Summerville this week. "This is Michael Moore talk!"

But Bush's clash with Trump may not have hurt the real estate billionaire enough to affect the outcome Saturday. Former South Carolina Gov. David Beasley said Trump's attacks on the Bush family's national security record may have had the unexpected effect of growing Trump's support in the state.

"Even for every point or two that it may have hurt Trump with the Bush voters who might be thinking of voting for Trump, I think it appealed to an extraordinary number of independent and conservative Democrats who didn't like the Bush and the war issue," said Beasley, who did not endorse a candidate.